Mr Elkin told Israeli Army Radio on Friday that if the international community failed to act over Syrian President Bashar Assad’s use of chemical weapons , it would send a signal to Iran that it could continue to develop its own nuclear weapons with impunity.

He pointed out that US President Barack Obama had defined use of chemical weapons as a "red line" that must not be crossed.

"There is a question here, when a red line is set can we stick by it?" he added. "If the Iranians will see that the red lines laid by the international community are flexible, then they will continue to progress [with their nuclear program me]."

Mr Elkin also raised concerns that Syria's chemical weapons could fall into the hands of the rebels fighting the goverment, or other forces potentially hostile to western interests. "The ease with which Mr Assad used chemical weapons shows that apparently it could easily pass it the hands of the other side."

Mr Elkin’s comments followed a briefing made by the Israeli Military Intelligence on Tuesday warning the Institute for National Security Studies about Syria’s use of sarin gas.